JP3380332B2 - Laminated metal plate with two-layer coating structure - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to processing corrosion resistance, durability,
The present invention relates to a laminated metal plate for a container which has excellent heat resistance during processing.

[0002]

2. Description of the Related Art Conventionally, in the can manufacturing industry, tin plates, electrolytic chromium treated steel plates (TFS), and metal plates such as aluminum have been coated once or plural times. Applying the coating a plurality of times as described above not only complicates the baking process, but also requires a large baking time. Moreover, since a large amount of solvent is discharged at the time of painting, there is an environmental and hygiene problem.

In order to solve these drawbacks, attempts have been made to laminate a thermoplastic resin film on a metal plate. In recent years, polyester films have attracted the most attention in terms of corrosion resistance, safety, and heat resistance in the printing process. As an example, a polyethylene terephthalate film is laminated on a metal plate without using an adhesive (Japanese Patent Publication No. 60-47103, Japanese Patent Publication No. 2-58094), or a polyester film is laminated on a metal plate using an adhesive. Japanese Patent Publication No. 4-74176, Japanese Patent Application Laid-Open No. 1-249331, Japanese Patent Publication No. 63-13829, Japanese Patent Publication No. 3-76830, and Japanese Patent Application Laid-Open No. 3-87249 have been disclosed. A laminate of a polyolefin film on a metal plate (Japanese Patent Laid-Open No. 53-141786, etc.)
Is also disclosed.

[0004]

However, the can obtained from these polyester laminated metal sheet or polyolefin laminated metal sheet has not only a low impact resistance of the film, but also continuous drawing-ironing (DI) processing. When a can-making process such as is performed, the film is melted by the heat generated when the laminated plate is stretched or the friction heat generated between the film and the can-making jig, or the film is fused to the can-making jig. There is a problem of peeling. In particular, a laminated metal plate is required which has a large heat generation amount on the outer surface side of the can and is not fused to a jig.

Further, a can made of these polyester laminated metal plate and polyolefin laminated metal plate is
It has a problem of low impact resistance. An object of the present invention is to provide a laminated metal plate for a container which can withstand severe can manufacturing such as drawing-ironing and has excellent impact resistance, durability and corrosion resistance.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, have reached the following inventions .

That is, the present invention is provided on at least one side of the metal plate.
Using the polycarbonate resin film layer (A1) as an outer layer,
A thermoplastic polyester resin film layer (A
In the laminated metal plate having 2), the thermoplastic polyester resin film layer (A2) has one or more saturated polyhydric alcohol components and terephthalic acid (T2).
PA) component and isophthalic acid (IPA) component copolymerized polyester film, and IPA / TPA = 0.02 to 0.42 (molar ratio), a laminate metal having a two-layer coating structure. plate, and a can or container.

In the present invention, the thermoplastic polyester resin film layer (A2) is a copolymer composed of one or more saturated polycarboxylic acid components, ethylene glycol (EG) components and diethylene glycol (DEG) components. A laminated metal plate and a can or container characterized by being a polyester film and having a ratio of DEG / EG = 0.02 to 0.42 (molar ratio).

In the present invention, the thermoplastic polyester resin film layer (A2) comprises one or more kinds of saturated polycarboxylic acid components, ethylene glycol (EG) components, 1,4-cyclohexanedimethanol (CHDM). And a CHDM / EG = 0.02 to 0.42 (molar ratio), a laminated metal plate and a can or container.

[0010]

The function of the present invention will be described in detail below. First, the outer polycarbonate resin film layer (A1) used in the present invention will be described. The outer polycarbonate resin film layer (A1) comprises various polycarbonate and copolycarbonate resins obtained by reacting a dihydroxy compound with phosgene or diphenyl carbonate by a known method.

The dihydroxy compounds include hydroquinone, resorcinol, 4,4-dihydroxy-diphenyl-methane, 4,4-dihydroxy-diphenyl-ethane, 4,4-dihydroxy-diphenyl-n-butane and 4,4-dihydroxy-. Diphenyl-heptane,
4,4-dihydroxy-diphenyl-phenyl-methane, 4,4-dihydroxy-diphenyl-2,2-propane (bisphenol A), 4,4-dihydroxy-
3,3-dimethyl-diphenyl-2,2-propane,
4,4-dihydroxy-3,3-diphenyl-diphenyl-2,2-propane, 4,4-dihydroxy-dichloro-diphenyl-diphenyl-2,2-propane, 4,
4-dihydroxy-diphenyl-1,1-cyclopentane, 4,4-dihydroxy-diphenyl-1,1-cyclohexane, 4,4-dihydroxy-diphenyl-methyl-phenyl-methane, 4,4-dihydroxy-diphenyl-ethyl -Phenyl-methane, 4,4-dihydroxy-diphenyl-2,2,2-trichloro-1,1-ethane, 2,2-dihydroxydiphenyl, 2,6-dihydroxynaphthalene, 4,4-dihydroxydiphenyl ether, 4, 4-dihydroxy-3,3-dichlorodiphenyl ether and 4,4-dihydroxy-2,5-diethoxyphenyl ether are used.

Among them, polycarbonate using 4,4-dihydroxy-diphenyl-2,2-propane (bisphenol A) is preferable in terms of availability of raw materials, mechanical properties such as impact resistance, and thermal properties. preferable. In addition, polyethylene terephthalate, polybutylene terephthalate, polystyrene, AB may be used as long as the object of the present invention is not impaired.
Other resin components such as S resin may be blended.

Further, the polyester resin component or the like may be copolymerized by a transesterification method or the like. Next, the thermoplastic polyester resin film layer (A2) as the inner layer used in the present invention will be described. The thermoplastic polyester resin film layer (A2) as the inner layer is used as an adhesive layer between the polycarbonate resin film layer (A1) as the outer layer and the metal plate. When there is no inner layer (A2), the adhesive strength between the metal plate and the outer layer is insufficient.

The thermoplastic polyester resin film layer (A2) of the inner layer constituting the present invention is a copolymer composed of one or more saturated polycarboxylic acid components and one or more saturated polyhydric alcohol components. In polyester
It Copolymerized polyester resin film layer (A
As the saturated polyhydric alcohol component constituting 2), ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, propylene glycol, polytetramethylene glycol, diethylene glycol, trimethylene glycol. , Polyethylene glycol, triethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethal, trimethylolpropane, pentaerythritol, etc. are available, but physical properties such as availability, heat resistance of the copolyester, and processability. Therefore, in the present invention, general ethylene glycol (EG), diethylene glycol (DE)
G), 1,4-cyclohexanedimethanol (CHDM)
Is preferably used.

The saturated polycarboxylic acid component constituting the copolyester resin film layer (A2) of the present invention includes phthalic acid, isophthalic acid, terephthalic acid, succinic acid, azelaic acid, adipic acid, sebacic acid, dodecanedione. Acid, diphenylcarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,
Trimellitic anhydride and the like can be mentioned, but terephthalic acid (TPA) and isophthalic acid (IP
A) is preferred.

The copolymerized polyester film (A
2) is an acid component, IPA / TPA = 0.02 to 0.42 (molar ratio) or a copolyester film (A2) is an alcohol component, DEG / EG = 0.02 to 0.42 (molar ratio) or a copolyester film (A2) A2) is an outer layer polycarbonate film (A1) when the alcohol component is CHDM / EG = 0.02 to 0.42 (molar ratio).
With the synergistic effect with, excellent adhesiveness, workability, corrosion resistance, and adhesion are exhibited.

More specifically, IPA / TP
When A, DEG / EG or CHDM / EG are each less than 0.02, the adhesive strength between the outermost polycarbonate film (A1) and the metal plate is insufficient and peeling of the film occurs. Also, IPA / TPA, DEG / EG or CH
When DM / EG exceeds 0.42, the heat resistance is insufficient and the high temperature (170-210
(° C) causes problems such as melting and shrinkage. In addition, since the barrier property is not sufficient, sub-film corrosion occurs.

From the above, IPA / TPA, DEG
/ EG or CHDM / EG is in the range of from 0.02 to 0.42 (molar ratio). As a range having more excellent physical properties, IP
A / TPA, DEG / EG or CHDM / EG is 0.08-
A range of 0.30 (molar ratio) is recommended.

Japanese Unexamined Patent Publication No. 62-94543 and Japanese Unexamined Patent Publication No. 2-3052
Thermosetting polyester resins such as polyester urethane type, polyester epoxy urethane type, and polyurethane polyol type, which are disclosed in Japanese Patent Publication No. 5 and Japanese Patent Publication No. 52-30028, which require a crosslinking reaction, or JP-A-4-1181.
The epoxy-based adhesive disclosed in Japanese Patent No. 21 is unfavorable from the viewpoints of residual uncured monomer and solvent, adhesion after retort treatment, moldability and corrosion resistance.

Further, Japanese Patent Laid-Open Nos. 64-27922 and 64,
The olefin-based adhesive disclosed in -27923 is not preferable in terms of heat resistance. The thermoplastic polyester resin (A2) used in the present invention comprises a saturated polyhydric alcohol component such as ethylene glycol, a saturated polyhydric carboxylic acid component such as isophthalic acid and terephthalic acid, and their substitution products as starting materials. It may be prepared by a known polymerization method such as an exchange method or a direct polymerization method, or may be prepared by blending a polyethylene terephthalate resin (or polybutylene terephthalate) and a copolyester resin. It can also be obtained by blending with two or more copolymerized polyester resins having different copolymerization ratios.

Further, a polyvalent saturated alcohol component of the thermoplastic copolyester resin (A2) used in the present invention,
The ratio of polyvalent saturated carboxylic acid component is a molar ratio, polyvalent saturated alcohol component / polyvalent saturated carboxylic acid component = 0.
The range of 95 to 1.05 (molar ratio) is preferable. The thickness of the resin layers of the outer layer and the inner layer is not particularly limited, but it is 8 depending on the balance between the processability of making the can and the adhesion between the resin layers and between the resin layer and the metal plate.
~ 100 μm, 1-30 μm, and total thickness 9-130 μm
Is preferred. More preferably, the outer layer has a thickness of 10 to 50 μm, and the inner layer has a thickness of 1 to 10 μm.

The outer and inner resin layers (A1, A2) used in the present invention are each one or more kinds of antistatic agents, lubricants, flame retardants and anti-reflective agents within a range not impairing the purpose of the present invention. A blocking agent (amorphous silica, zeolite, amorphous alumina silica, etc.), a coloring pigment (titanium dioxide, barium sulfate, etc.), an antioxidant, an ultraviolet absorber, an inorganic filler, and other resins may be contained. Particularly when white coating is applied to the outer surface of the can, white coating can be omitted by adding titanium dioxide powder as a white pigment to the outer layer (A1).

Further, a chemical treatment method (chemical treatment, solvent treatment, primer or polymer coating, adhesive coating, coupling agent treatment, surfactant treatment, surface grafting, colloid) is applied to the contact surface of the film with the metal plate. Treatment) and / or a physical treatment method (UV irradiation treatment,
The surface may be modified by plasma contact treatment, corona discharge treatment, etc.).

Next, the metal plate used in the present invention will be described. Examples of the metal plate used in the present invention include sheet-shaped and coil-shaped steel plates, steel foils and aluminum plates, or those obtained by subjecting these metal plates to surface treatment. The thickness of the metal plate is not particularly limited, but 0.1 to 0.5 mm is preferable from the viewpoint of balance between can strength and light weight.

The metal plate used in the present invention is an electrolytic chromic acid-treated steel plate having a two-layer structure in which the lower layer is metallic chromium and the upper layer is chromium hydrate oxide in view of corrosion resistance, can-making processability, can strength and corrosion resistance. (TFS), or a steel sheet having a surface treatment of a metal chromium layer and a chromium hydrated oxide layer on an island-shaped tin layer, a tin-plated steel sheet, an ultra-thin tin-plated steel sheet, a nickel-plated steel sheet, a galvanized steel sheet and their plating. Steel sheet with chromium hydrated oxide, or surface-treated with two-layer structure consisting of chromium hydrated oxide as the upper layer and metallic chromium layer as the lower layer, or phosphate treatment, chromic acid treatment, chromium-chromate treatment An aluminum plate or the like that has been treated can be used.

The method for producing the laminated metal sheet of the present invention is not particularly limited, but 1) a method of heating the metal sheet to a temperature equal to or higher than the melting point of the inner layer and then adhering the two-layer film from the beginning, 2 ) A method of heating the metal plate to a temperature equal to or higher than the melting point of the inner layer, and then simultaneously adhering the inner layer film and the outer layer film to each other. Examples of the method include a method of adhering the outer layer film in a state where the temperature is kept above the melting point of the inner layer, and the like, but the method 1) is most preferable from the viewpoint of productivity and economical efficiency.

The steel plate heating device is not particularly limited, but a heating furnace, an induction heating device, a heating roll and the like are preferable. The laminating apparatus is not particularly limited, but a method using a laminating roll capable of temperature control is preferable. Further, after lamination, a method of quenching with a cooling roll, a cooling water tank or the like is preferable in order to prevent recrystallization of the film.

The laminated metal sheet of the present invention is excellent in can-making processability and is most suitable for the outer surface of the can, but it is also excellent in corrosion resistance and can be applied to the inner surface of the can. The laminated steel sheet of the present invention is a well-known draw-ironing (DI) can, draw can, draw-redraw (DRD) can, or thin-walled draw (DT).
R) Preferred for cans. Known adhesive cans and welded cans may be produced by using the laminated metal sheet of the present invention as a can body. In the case of an adhesive can, the outer layer coating on the outer surface of the can and the outer layer coating on the inner surface of the can may be superposed, heated and fused to bond them together. Further, the laminated metal plate of the present invention may be used as a can lid.

It can also be used as containers such as trays for microwave ovens, electronic and electric fields, steel plates for automobiles, building materials and structural materials.

[0030]

[Examples 1-35, Comparative Examples 1-33]

(1) Manufacturing method of laminated metal plate A strip-shaped metal plate having a width of 300 mm was continuously heated using a heat roll. The heated metal plate was sent to a laminating roll, and each film was continuously heat-sealed on one side or both sides. As the film, a film having a two-layer structure or a monofilm was used from the beginning. The films used in the experiment are shown in Table 2.

The material of the laminating roll was silicon rubber. After fusion, the laminated metal plate was rapidly cooled with a cooling roll. The laminating speed was about 30 m / min. The films used in the experiment and the metal plate temperatures immediately before lamination are shown in Tables 3 to 9. The polycarbonate resin films used in the experiments were all polycarbonate resins obtained by a known reaction of bisphenol A and phosgene.

(Examples 1-9, 19-27, Comparative Examples 1-11,
23-33) Using a double-sided electrolytic chromic acid treated steel sheet (TFS) having a lower layer of chromium metal of 110 mg / m ² and an upper layer of chromium hydrated oxide of 18 mg / m ² , the results of Tables 3, 4, 7 and 8 Lamination was performed under the conditions. The tempering degree of TFS is T-4, and the plate thickness is
It was 0.25 mm. (Examples 10 to 18, Comparative Examples 12 to 22) The amount of tin deposited is 2.8 g / m.
² , the tinplate having the amount of metallic chromium of the outermost layer of 35 mg / m ² and the amount of hydrated chromium oxide of 18 mg / m ² was used.
Lamination was performed under the conditions of. Tin temper is T-
1. The plate thickness was 0.30 mm.

(2) Can-making method For Examples 1 to 18 and Comparative Examples 1 to 22, from the obtained laminated metal plates, a known squeeze-ironing (DI) was performed so that the laminating surface was the outer surface of the can. Depending on processing, can diameter 211
A φ (350 ml beer can size) DI can was obtained. The can making speed was 200 cans / minute, 10,000 cans were continuously made, and 10,000 samples were used as evaluation samples.

Regarding Examples 19 to 27 and Comparative Examples 23 to 33,
A DRD can having a can diameter of 211 φ (350 ml beer can size) was obtained from the obtained laminated metal plate by a known drawing-redrawing (DRD) process so that the laminating surface became the outer surface of the can. The can making speed was 200 cans / minute, 10,000 cans were continuously made, and 10,000 samples were used as evaluation samples. (3) Evaluation method i) Evaluation of formability The state of the film and the forming jig after can making were visually observed.

Ii) Evaluation of Film Adhesion The cans after the canning were subjected to retort treatment. The processing conditions were 110 ° C. for 1 hour. 50 cans of processed cans
Cut out to 50 mm, and cut the laminated board with J
According to IS-5400, 10 mm substrate-like cuts were made at 1 mm intervals, and then the tape was peeled off.

Table 1 shows the evaluation criteria.

[0037]

[Table 1]

(Examples 28 to 35) iii) Actual Can Test For Examples 28 to 35, the obtained cans were filled with a commercial cola, double-tightened, and stored for a long time at 38 ° C. ,
The corrosion state of the inner surface of the can was observed. Examples of the present invention include
All of them have excellent workability and adhesion, and further have excellent corrosion resistance as compared with Comparative Examples. Surprisingly, the fusion of the film did not occur due to the heat generated by the continuous molding.

It is considered that the cause is that a clear melting phenomenon did not occur because the surface polycarbonate resin was amorphous and had a very high melt viscosity.

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

[Table 5]

[0044]

[Table 6]

[0045]

[Table 7]

[0046]

[Table 8]

[0047]

[Table 9]

[Examples 36 to 42, Comparative Examples 34 to 37] (1) Method for producing laminated metal plate A strip-shaped metal plate having a width of 300 mm was continuously heated using a heat roll. The heated metal plate was sent to a laminating roll, and each film was continuously heat-sealed on both sides. As the polycarbonate film, a film having a two-layer structure was used from the beginning. The material of the laminating roll was silicon rubber. After laminating, the laminated metal plate is rapidly cooled to 30 ° C. in 5 seconds in a water bath. The laminating speed was about 30 m / min.

The films used in the experiments are shown in Tables 10 and 11, and the metal plate temperature immediately before lamination is shown in Table 13. The inner layer films of the films R to Y used ethylene glycol as a saturated polyhydric alcohol component, and the films of Z and Z1 used terephthalic acid as a saturated polyhydric carboxylic acid component. The polycarbonate resin film used in the experiment was
All were polycarbonate resins obtained by a known reaction of bisphenol A and phosgene.

[0050]

[Table 10]

[0051]

[Table 11]

In the experiment, the amount of metallic chromium in the lower layer was 110 mg /
m ^2, and using the upper layer of hydrated chromium oxide content 18 mg / m ² in a double-sided electrolytic chromic acid treated steel sheet (TFS). The tempering degree of TFS was T-4, and the plate thickness was 0.245 mm. (2) Can-making method In Examples 36 to 42 and Comparative Examples 34 to 37, a circle diameter of 211 was obtained from the obtained laminated metal plate by a known DI processing method.
A DI can of φ (350 ml beer can size) was obtained.

10,000 cans were continuously produced at a rate of 200 cans / minute, and the 10000th can was used as an evaluation sample. Further, in Example 42, a DRD can having a diameter of 211 (350 ml beer can size) was obtained from the obtained laminated metal plate by a known DRD processing method. Continuously at a speed of 200 cans / minute 1
0000 cans were made, and the 10000th can was used as an evaluation sample.

(3) Evaluation method i) Evaluation of moldability The inside and outside of the can after the can making was visually observed. In addition, in order to check the soundness of the can, a 1% NaCl solution was put in the can, and the current value flowing when a voltage of +6 V was applied with the can body as an anode and the carbon rod as a cathode (hereinafter, ERV test). And).
The smaller the ERV value, the smaller the coating defects and the higher the soundness of the can.

Ii) Assuming heating in the heat-resistant printing process, the film was left in an oven set at 180 ° C. for 10 minutes, and the presence or absence of melting of the film was visually observed. iii) Evaluation of film adhesiveness The cans after the can making were subjected to retort treatment. The treatment condition was 110 ° C. for 1 hour. 50 × the can body of the treated can
Cut to 50 mm, JIS
In accordance with -5400, after making 10mm board-like cuts at 1mm intervals, make a DuPont impact test (J
IS-5400) was performed. Punch diameter is 1/4 ", load is 300g,
The height was 20 cm. A tape peeling test was performed on the DuPont processed part.

Table 12 shows the evaluation criteria.

[0057]

[Table 12]

Iv) Impact resistance test A DuPont impact test (JIS-5400) was performed on the center of the can body. The punch diameter was 1/4 ", the load was 300 g, and the height was 20 cm. The ERV test was performed on the cans after the impact test v) Actual can test Examples 36 to 42 and Comparative Examples 34 to 37 The obtained can was filled with a commercially available cola, double-tightened, and stored for a long time at 38 ° C., and the corrosion state of the inner surface of the can was observed.

The experimental results are shown in Table 13.

[0060]

[Table 13]

Each of the examples of the present invention exhibited excellent workability, adhesion, heat resistance, and further excellent corrosion resistance and impact resistance, as compared with the comparative examples, and were extremely excellent properties as a can material. And the balance of physical properties are shown. And surprisingly,
No film fusion occurred due to the heat generated by continuous molding. It is considered that the cause was that no clear melting phenomenon occurred because the surface polycarbonate resin was amorphous and had a very high melt viscosity.

[0062]

The can and container made of the laminated metal plate and the laminated steel plate obtained in the present invention have impact resistance,
It has excellent processing corrosion resistance and adhesion, and also has good continuous formability. This makes it possible to provide more durable and reliable cans, can bodies, and can lids. Further, it is considered that the laminated metal plate of the present invention can be applied to a tray for microwave oven, electric field, automobile field, building material and the like.

Front Page Continuation (72) Inventor Kazuo Mochizuki 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Steel Development & Production Division Steel Research Laboratory (72) Inventor Hajime Ogata 1 Kawasaki-cho, Chuo-ku, Chiba-shi Address Kawasaki Steel Mfg. Co., Ltd. Steel Development and Production Division, Chiba Steel Works (56) References: 60-118295 (JP, U) Special Table, 4-500185 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00

Claims (2)

(57) [Claims] 1. A least a metal plate one side polycarbonate resin film layer of the (A1) and an outer layer, in Lula <br/> laminate-metal plate Yusuke its inner thermoplastic polyester resin film layer (A2), the thermal Plastic polyester tree
The fat film layer (A2) is saturated with one or more kinds.
Polyhydric alcohol component and terephthalic acid (TPA) component
Copolyester composed of sophthalic acid (IPA) component
Film and IPA / TPA = 0.02 to 0.42 (molar ratio), or the thermoplastic polyester resin film layer (A
2) is one or more saturated polycarboxylic acid compounds.
Minutes, ethylene glycol (EG) component and diethylene glycol
Copolyester fiber composed of coal (DEG) component
Rum and DEG / EG = 0.02 to 0.42 (molar ratio), or the thermoplastic polyester resin film layer (A
2) is one or more saturated polycarboxylic acid compounds.
And ethylene glycol (EG) components and 1,4-cyclohexene
A copolymerized copolymer consisting of xanthimethanol (CHDM) component
Laminate having a two-layer coating structure , which is a polyester film and has CHDM / EG = 0.02 to 0.42 (molar ratio)
Metal plate. Wherein cans or containers made of laminated metal sheet of claim 1 Symbol placement.